JP2003185474A - Multiple resolution photodiode sensor array for optical encoder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of controlling the resolution of an optical encoder for providing position information of a body moving in a specified measuring direction. <P>SOLUTION: The optical encoder has a light source for emitting light and data tracks moving, relative to the light source. The method comprises pointing light from the data track on the plurality of photodiodes having a first resolution value, and changing the resolution of the detector system to a second value, without changing the layout of the plurality of photodiodes in the detector system during changing from the first value to the second one. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to photodiode sensors used for various optical resolutions. In particular, the invention relates to photosensor arrays for optical encoders used for different resolutions.

[0002]

Optical encoders are known for measuring the relative position between two movable objects. Just as it is possible to measure relative position along the direction of rotational movement, it is possible to measure relative position along the direction of linear movement.
In this system, one object is often connected to a scanning scale, while the other object is connected to a scanning unit. In the case of a linear encoder, a linear scale with a linear scale is used, while in the case of a rotary encoder, a code disk with a circular scale is used. The scanning unit used for linear or rotary movement has one or more light sources and one or more photoelectric detection elements. For example, photodiodes are often used as sensing elements.

In recent years, linear encoders and rotary encoders in which a large number of photodiodes as detection elements are combined with each other have become more and more popular. Such a detection arrangement is sometimes also referred to as a phased array. Such encoders and detectors are described in US Pat. No. 6,175,109. The entire content of this is described herein by reference.

In the embodiment of the detector arrangement described above,
A plurality of photodiodes are arranged in an array on the semiconductor chip. The placement of these photodiodes is
It must be ordered / designed for each encoder configuration in a unique way. This means that the geometrical arrangements required of the photodiodes, such as the width and the spacing of the photodiodes, depend on the scanning arrangement, in particular the graduation period of the scanning graduation being scanned. There is a well-defined arrangement of photodiodes for a given measurement resolution. Therefore, if it is necessary to change the scanning arrangement or the resolution of the encoder, it is necessary to change the arrangement of the photodiodes to obtain the desired scanning arrangement or resolution. In this case, a lot of design work is required to change the layout of this photodiode array.

To solve this problem, EP 0 710 819 uses a single photodiode assembly with several photodiodes for several different scanning graduations exhibiting different graduation periods. Advocate to do. For this purpose, only a certain number of available photodiodes have to be activated depending on the scanning scale.
A matching process is required to determine in each case which of the photodiodes has to be activated for a particular scan scale.
The requirement of a complex ASIC to control this adaptation process is a major drawback of this system. Another drawback is that the system's adaptation phase requires special tooling discs. In addition, circuitry associated with large memory space is needed on the carrier substrate. This carrier substrate goes against the possible miniaturization of the system.

Another drawback of the system described in EP 0 710 819 is the index sensor of the system for measuring absolute position. In particular,
A disc having a pattern of openings that matches the pattern of the index sensors allows light to pass through these index sensors. This light is 1
The index sensor is illuminated at only one point per revolution.
The signal when part of the index sensor is illuminated is significantly smaller than when the entire index sensor is illuminated at the same time.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to allow a detector array to be made as compact as desired while at the same time easily changing the resolution of the detector array.

Another object of the invention is to change the resolution of the detector array without using adaptive phases.

Another object of the invention is to improve the strength of the absolute and relative position signals produced by the detector array at multiple resolutions.

A first aspect of the present invention relates to an optical encoder that provides position information of an object moving along a particular measurement direction. The encoder has a light source that emits light and a data track attached to an object that moves relative to the light source. The data track has a plurality of variable regions that receive light and exhibit different optical properties with a particular resolution. A detection system receives the modulated light from the data track and produces a position signal from the received light. The detection system has a photodiode array that receives the modulated light from the data track and a resolution selection unit connected to the photodiode array. This resolution selection unit controls the resolution of the photodiode array. In this case, all photodiodes associated with the photodiode array are
It is activated regardless of the resolution selected by the resolution selection unit.

A second aspect of the present invention relates to a method of controlling the resolution of an optical encoder that provides position information of an object moving along a particular measurement direction. In this case, the optical encoder has a light source that emits light and a data track that moves relative to this light source.

A third aspect of the present invention relates to an optical encoder that provides position information of an object. The optical encoder has a light source that emits light and a data track mounted on an object that moves relative to the light source. The data track receives light and has alternating regions of different optical properties with a particular resolution. The detector is
Light is received from the data track and an index signal is generated from the received light. The detection system includes an index photodiode array that receives light from the data track and generates an index signal, and a resolution selection unit connected to the index photodiode array. This resolution selection unit controls the index signal.

A fourth aspect of the present invention relates to a method of controlling an index signal of an optical encoder which provides position information of an object moving along a predetermined measuring direction. In this case, the optical encoder has a light source that emits light, and a data track that moves relative to the light source and exhibits a given resolution. This method detects light from a data track to a plurality of photodiodes of the index photodiode array without changing the arrangement of the photodiodes of the index photodiode array, and
An index signal is generated by changing the active state of one or more photodiodes.

Aspects of the present invention allow the detector array to be appropriately sized and compacted while easily altering the resolution of the detector array.

Aspects of the invention provide the advantage of not requiring a matching phase to determine which photodiode in the array to activate for a particular resolution. The elimination of the activation phase further provides the advantage that no special tooling disc is required as is required for the system described in EP 0 710 819.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS These matters and other features and advantages of the present invention will be described in detail below with reference to the drawings.

FIG. 1 schematically shows a cross section of an optical encoder of the preferred embodiment of the present invention. In particular, the optical encoder shown is a rotary encoder 100 that produces position information about the motion of two rotating objects. Rotary encoder 100 may be used, for example, in applications involving brushless motors.

The optical encoder 100 is shown in FIGS.
It includes a code gear 102 having a single data track 104 as shown in 6,8,9,11. The code gear 102 is mounted on a shaft (not shown) that rotates around an axis and moves / rotates along the measuring direction. The rotating shaft may be the rotor of a brushless DC motor. Further, the optical encoder 100
It has a scanning unit 106 for photoelectrically scanning the data tracks 104. As shown in FIG. 1, the scanning unit 106 has a light source 110 and a lens 112, preferably a condenser lens or a focusing lens. The structure of encoder 100 is shown only schematically, as the mechanical details of the structure are well known to those skilled in the art.

As shown in FIGS. 1 and 2, the light 114 emitted by the light source 110 is collimated by the condenser lens 112 and transmitted through the data track 104 of the code gear 102 which rotates with respect to the light source 110. It The light 116 modulated by the rotating data track 104 is reflected by the photodetector array 118 of the detection system 120.
Received by. The detected signal is processed in an evaluation unit not shown in FIGS.

As shown in FIGS. 1-3, 5, 6, 6, 8, 9, and 11, the data tracks 104 have different optical characteristics, such as alternating transparent bars 122 and opaque bars 124. With an alternating pattern of alternating regions of. If the optical encoder 100 is configured to use an incident light data track, then the data track can be composed of alternating high and low reflectivity regions. In addition, the photodetector array 118 includes one incremental photodiode array 12
6 and 2 index photodiode arrays 12
It is composed of 8,130. Photodiode array 1
26, 128, and 130 have a plurality of photodiodes 132, 134, 136, respectively. These photodiodes 132, 134, 136 are opt-ASI.
It is arranged in a separate array on the C semiconductor chip 138. This opto-ASIC semiconductor chip 138 is P
It is mounted on the C board 139.

As shown in FIGS. 3-11, the incremental photodiode array 126 has 96 photodiodes 132. In this case, adjacent photodiodes are arranged equiangularly with each other. And these photodiodes as a group have an angle of about 9.2 °,
For example, define the angle range of 9.22 °. As a result, the individual photodiodes have a pitch corresponding to the desired maximum resolution, such as 1012. Adjacent photodiode 1
The linear spacing between 32 is constant. The minimum spacing between adjacent photodiodes 132 is approximately 5 due to the molding process design rules that limit the maximum width of the photodiodes.
μm. Each set or group of four photodiodes is arranged within one grating period of the code disc pattern. Adjacent photodiodes within each set are arranged relative to each other. As a result, there is a 90 ° phase lag between the output signals of adjacent photodiodes. Therefore, four adjacent photodiodes have relative phases of 0 °, 90 °, 180 ° and 270 °. These signals with different phases are shown in FIGS.
A in 9 and 11! , B, A, B! Is written.

The incremental photodiode array 126 is
It has 16 conductors 140. These conductors 140 are
It is internally connected to a photodiode 132 and a conductor 142 extending from three incremental data resolution selection units 144, 146, 148. 3, 4, 6, 7,
As shown in FIGS. 9 and 10, each incremental data resolution selection unit 144, 146, 148 includes 16 conductors 150.
Have. These conductors 150 are connected to a group of 16 conductors 140 and to four output signal lines 152.

Each incremental data resolution selection unit 14
4, 146 and 148 are switching signal lines 1 respectively
54, 156, 158. Switching signal line 1
54, 156 and 158 are 16 semiconductor switches 16
0 to selectively connect to conductors 150 associated with the incremental data resolution selection unit corresponding to these switching signal lines. Each of the semiconductor switches 160 is always on or off. Semiconductor switch 1
60 is used to connect the 16 conductors 140 to the four output signal lines 152 in different combinations. Each of the output signal lines 152 has an incremental scanning signal A, B,
A! , B! Is output. While these aforementioned switches are semiconductor switches, other switches are possible, such as switches that include metal links.

As shown in FIGS. 3, 5, 6, 8, 9, 11, and 12A, the index photodiode array 128 and the index photodiode array 1 are shown.
A photodiode 134 associated with 28 produces a first index signal Z. Then, the index photodiode array 130 and the 14 photodiodes 136 of the index photodiode array 130 are provided.
However, the second index signal Z! To generate. Individual photodiodes in the index photodiode arrays 128, 130 are enabled by the same signal. This same signal enables the individual photodiodes 130 of the photodiode array 126. These individual photodiodes 130 are activated to achieve the desired encoder resolution.

When the encoder is fully rotated, the index signals Z and Z! Outputs a special pattern. In particular,
Index signal Z, Z! Are electrically compared and processed to output one output pulse per revolution of the encoder 100. The encoder 100 absolutely locates all the other signals of the encoder.

Therefore, the index signals Z, Z! Is fully differential. Z! The code disc pattern for the signal has an opaque area in every part. The code disc pattern for the Z signal has an opening on the contrary. Such differential characteristics eliminate common mode noise. Index signal Z, Z! Is used to determine absolute information. This unique pattern is created by a special optical pattern. This special optical pattern is optimized in order to achieve a pulse with maximum contrast between a single optical cycle and the "background" signal that is always present. This definition depends on this optical cycle. In order to be flexible in the choice of resolution to be detected according to the invention, it is necessary to change the index signal based on the chosen resolution. As a result, differently optimized patterns can be used for each resolution. Therefore, depending on whether the particular pattern to be detected requires an output signal, the signals from the detectors of array 128, 136 are sent to this output signal.

Index / photodiode array 1
28 photodiodes 136 of 28 are arranged. As a result, these photodiodes 136 have corresponding openings or bars 122 in the data track 104.
When fully illuminated through, a single large index pulse is generated or formed. Similarly,
The photodiodes 134 of the index photodiode array 130 are arranged. As a result, a single large index pulse is generated or formed when these photodiodes 134 are fully illuminated through the corresponding openings or bars 122 in the data track 104. The light received by the index photodiode arrays 128, 130 is unmodulated. Good contrast between index signals
The angular width of the index photodiode arrays 128, 130 is chosen to be realized over a range of resolutions. Each of the photodiodes 134 and 136 has a width of about 68 μm. A non-conductive material is used to form the adjacent photodiode 134 and photodiode 136.
Exists between and. As a result, these adjacent photodiodes are approximately 5.8 μm apart. Each of the index photodiode arrays 128 and 130 has 10
They are arranged at a pitch that matches one data region (360 ° e) of the desired highest resolution, such as 12. The photodiodes 134 and 136 are the photodiodes 13.
It has a radial pitch equal to 4 times the pitch of 2. Due to the various scanned structures on the code disc,
Various index signal waveforms Z, Z! Occurs. Due to the availability of code discs with multiple different resolutions, 14 photodiodes 134 and 14 photodiodes 136 are selectively activated to provide the sharpest index pulse for the unique code disc 102. To realize. However, the general principle of generating these signals is common to both index signal photodiode arrays 128, 130.

In the angle optical encoder as shown in FIGS. 1-13A-B, the photodiode arrays 126, 1
28 and 130 need to have one axis in common. These photodiode arrays 126, 128, 130
The angular relationship between them need not be special values, but must be constant and known values.

Index / photodiode array 1
The inevitable relationship between 28, 130 and the incremental photodiode array is that the individual index array elements 13
A radial pitch of 4,136 has an incremental array element 1
It is four times 32 pitches or one data cycle wide. The pattern of the index array for all possible encoder resolutions is the index detector element 1
Each resolution requires a different combination in order to obtain the maximum single signal from the available detector elements, as they need to be made from the same array of 34,136.

Signals A, A! From the incremental photodiode array 126, as shown schematically in FIG. 13A. ，
B, B! Are amplified by the impedance conversion amplifier 200. Then, the complementary signals A, A! And B, B!
Are compared with each other via the comparator 201. Similarly,
Index / photodiode arrays 128, 130
The signals Z, Z! Are amplified by the impedance conversion amplifier 202 and compared by the comparator 203. Then, the signals from the comparators 201 and 203 are input to the data processing element 204. To output for the detected frequencies 1X, 2X, 4X, 8X, this data processing element 204 includes all 16 output signals 206 that are properly phase-locked from the 16 phase-locked analog voltage signals. Is output. The output signal 206 is output to the digital logic unit 214. This digital logic 214 is programmed with these output signals 206 and the interpolator 216 to produce a high frequency signal by combining four fundamental signals that are 90 ° apart from each other (regardless of the resolution selected). Interpolation selection (inter
polation choices). Several output signals originate from chip 138, as shown in FIG. 13A. For example, two digital 50% duty cycle data pulses 218, 220 are output with a 90 ° offset. Furthermore, the signals AB or A! B! A single digital index pulse output at is generated. Digital output, analog test mode 1 for testing and evaluation purposes
And three programming such as analog test mode 2 are possible at the output terminals 230, 232, 234 as indicated by the labels for the outputs separated by /.

The resolution selection of the arrays 126, 128, 130, as well as many other selectable options in electron optics, are performed through the serial test and programming interfaces 212, 138.

The single-ended communication unit 224 shown in FIG. 13B.
Is the same for all resolutions. Communication unit 224
Produces three signals that are each electrically 120 ° out of phase. These three signals are generally referenced to the rising edge of the index signal and are used to center the motor on which the encoder is mounted. A method of obtaining a quasi-common mode reference signal between three single-ended communication signals is described in US Pat.
36,236 and 6,175,109. All of these contents are hereby quoted. The above method of generating the common mode reference signal is
It can be implemented using CMOS technology.

Photodiode arrays 126, 128,
Given the above description of 130, the ability to change resolution while using the same photodiode array 126, 128, 130 will be described below. Particularly preferably,
There is always a fixed number and arrangement of index and signal photodiodes 134, 136. With the above description and the resolution of the following N means, the data track 1 to be scanned is
A full circumference of 04 has a total of N alternating transparent bars 122 and opaque bars 124.

When the resolution of 1012 is realized when the data track has the resolution of 1012, the incremental data resolution selection unit 144 uses the ASIC semiconductor chip 1
It is activated via the activation signal generated by the 38 resolution selection logic and transmits along the switching signal line 154. Upon receiving the activation signal, the incremental data decomposition selection unit 144 opens or closes the semiconductor switches 160 of the individual units 144. As a result, a particular combination of 16 conductors 140 is connected to 4 output signal lines 152.
To achieve a resolution of 1012, an incremental data resolution selection unit 144 groups photodiodes 132 together. As a result, four adjacent photodiodes are continuously formed in groups of four. As shown in FIGS. 3 and 4, each group of four photodiodes is connected to the output signal line 152. As a result, the signal from the first photodiode in the group is
A! The signal from the second photodiode of this group is sent to the output signal line 152 and the B output signal line 152
Signal from the third photodiode of this group is sent to the An output signal line 152, and the signal from the fourth photodiode of this group is sent to the B! It is sent to the output signal line 152. As shown in FIGS. 3 and 4, as a result of such connection, a large number of photodiodes 1
32 is interdigitated with each fourth photodiode 132 acting as a group of photodiodes and connected to a single output signal line 152.

Further, the index resolution selecting unit 153 is provided with an index / photodiode array 12.
A particular photodiode of the 8, 130 photodiodes is selected for a particular resolution. in this case,
All photodiodes are activated at the time of selection. Such selection is performed via the switching signal line 154 and the switch 160 '. The activated photodiodes 1, 14, 15 are always connected to the switching signal lines 154, 156, 158 for all resolutions. For the remaining activated photodiodes, photodiodes 2, 12 have two separate lines connected to switching signal lines 156, 158 and switch 160 '. Photodiode 3,8,10
Has a separate line connected to switching signal lines 154 and 158 and a switch 160 '. The photodiode 4 is connected to the switching signal line 1 via the switch 160.
It is connected to 54. Photodiodes 5, 6, 11
Is a switching signal line 15 via a switch 160 '.
Connected to 6. Then, the photodiode 9 is
It is connected to the switching signal line 158 via the switch 160 '. When a resolution of 1012 is desired, the index selection unit 153 causes the switching signal line 15
4 activates a particular switch 160 '. As a result, as shown in FIGS. 3, 5 and 12B, the photodiode Nos. Of the index photodiode arrays 128 and 130 are not shown. Only 1,3,4,9,10,13,14 are selected. Switching signal line 154 and switch 1
60 'is programmed for a particular resolution via external code feed through a serial interface. The resolution of the photodiode arrays 128, 130 are simultaneously selected by the same coded programming signal that selects the resolution of the incremental photodiode array 126.

The photodiodes activated through the resolution selection unit 153 in the index photodiode array for a particular resolution are determined by determining the combination of photodiodes that optimizes the index signal for a particular resolution. It In other words, the photodiode is selected to give the largest ratio of the large center signal to the smallest signal immediately next to it for a particular resolution. A computer program may be prepared to compare the combinations of these photodiodes and select the optimal ratio combination as the matching disk pattern passes over the photodiodes.

For a resolution of 1012, a 1012 count disk passes over 14 photodiodes, as shown in FIG. After testing all possible combinations, No. 7 of 1, 3, 4, 8, 10, 13, 14
The optimum ratio is determined when the individual photodiodes are activated. When the disc pattern and the sensor pattern overlap, this combination becomes the central signal from the seven photodiodes. As the disk approaches and moves away from the center position, the two diodes coincide with the disk pattern maximum. The result is a signal to non-signal ratio of 7: 2. This difference is not the strength of 7 diodes,
Allows the electronics to process only the center signal with the desired width of a single data cycle.

For a resolution of 506, the data cycle is
That is twice the width of 1024 individual photodiodes. To compensate for the length of this data cycle, adjacent photodiodes of 14 individual photodiodes are grouped together. Each pair of photodiodes in a group is treated as a single photodiode for 506 resolution. Therefore, the optimum index signal must be determined for seven photodiodes in such a pair / group. The optimum signal to non-signal ratio is 4 groups of photodiodes 1 & 2,5 &
6, 11 & 12, 13 & 14 506 resolution configuration is selected. The result is a signal to non-signal ratio of 4: 1.

For a resolution of 253, the data cycle is
That is four times the width of 1024 individual photodiodes. However, an array of 14 individual photodiodes is only 3.5 253 resolution cycle width. Since it is not possible to group detectors next to each other in 3.5, we compromise by grouping detectors next to each other. As a result, the 253 resolution detectors are separated by a 253 resolution pitch, while being three 253 resolution cycle widths. As a result, four groups of four virtual photodiodes are formed. in this case,
The width of each virtual photodiode is equal to 3/4 of the actual photodiode width. 3 out of 4 groups
When one is selected, the optimal index signal is found based on the configuration described above. These three groups are photodiodes 1, 2 &3;8; 9 & 1
0; 12, 13, & 14 The result is a signal to non-signal ratio of 3: 1.

The resolution can be changed from any one of the resolutions 1012, 506, 253 to any of the other resolutions. Other resolutions are possible for the incremental photodiode array 126, for example, when other code gears 102 are used or other resolutions are used for the code gears 102. Such resolution is realized by activating the semiconductor switch 160 of the corresponding incremental data resolution selection unit and turning on all of these switches to select the required resolution. Therefore, the resolution can be changed without changing the placement of the photodiodes in the photodiode array 126. The semiconductor switch 160 is
Triggered by the resolution selection logic. This resolution selection logic is implemented in the same opto ASIC semiconductor chip 138 previously described.

An example of changing the resolution of the photodiode array 126 is shown in FIGS. 6-8. In this example, the resolution of 506 is the resolution switching signal line 156.
Is activated by sending an activation signal along. This switching signal line 156 causes the incremental data resolution selection unit 146 to open and close the semiconductor switch 160 of this unit 146. As a result, a particular combination of 16 conductors 140 will produce four output signal lines 1
Connected to 52. In particular, the incremental data resolution selection unit 146 defines a group of photodiodes 132 within the photodiode array 126. as a result,
Each of the eight photodiodes that are adjacent to each other is formed into one group. Therefore, 12 groups of 8 photodiodes are formed. As shown in FIG. 7, each group of eight photodiodes is connected to the output signal line 152. As a result, the signals from the first two photodiodes in the group are A! The signal from the second photodiode pair in this group is sent to the output signal line 152, and the signal from the third photodiode pair in this group is sent to the B output signal line 152. Sent to
And the signal from the fourth photodiode pair in this group is B! It is sent to the output signal line 152. Essentially, if the photodiodes are paired, the output signal A! ，
A, B! , B, the effective size of the detection area corresponding to the photodiode is doubled. Therefore,
The resolution of the array is doubled. Furthermore, FIGS.
As shown in 2C, the index array 128,
No. 130 photodiode No. 1, 2, 5, 6, 11
Only -14 is selected by the index resolution selection unit via resolution switching signal line 156.

In another example, 253 resolutions are activated by sending an activation signal along resolution switching signal line 158. This switching signal line 158
Causes the incremental data resolution selection unit 148 to open and close the semiconductor switch 160 of this unit 148. As a result, a particular combination of 16 conductors 140 is connected to 4 output signal lines 152. In particular,
Incremental data resolution selection unit 148 defines a group of photodiodes 132 within photodiode array 126. As a result, each of the 16 photodiodes which are adjacent to each other in series is formed into one group. Therefore, 6 groups of 16 photodiodes are formed. As shown in FIGS. 9 and 10, each group of 16 photodiodes is connected to the output signal line 152. As a result, the signals from the first four photodiodes in the group are A! The signals from the second four photodiodes of this group are sent to the output signal line 152, and the B output signal line 152
Signal from the third four photodiodes of this group is sent to the A output signal line 152, and the signal from the fourth four photodiodes of this group is B! It is sent to the output signal line 152. further,
Index / photodiode arrays 128, 130
Photodiode No. 1-3, 8-10, 12-1
Only 4 is selected by switching the switching signal line 158 and the switch 160 'via the index resolution selection unit 153.

While the above example demonstrates changing the resolution of the incremental photodiode array 126, a suitable combination of available index photodiodes 134, 136 to produce an index signal with the appropriate resolution. It is also possible to select.

In the above example, a low resolution of 506, 253 is produced by doubling the grouping of photodiodes 132. Naturally, the photodiode 132
1-13 by forming a group with an integer N
Other resolutions are possible using the same principles described above for the AB examples. Here, N = 3,4,5,5
…, Etc.

The advantage of the above example is that the four output signals A,
A! , B, B! In that the total number of photodiodes connected to each is constant regardless of the resolution selected for the optical encoder 100. Further, all photodiodes 132 are used for each resolution selected by optical encoder 100. This is
In contrast to the system described in EP 0 710 819 in which the array elements are activated on the basis of the matching phase. In this matching phase, the photocell assembly is scanned and the output of the photocell assembly is evaluated. In the example previously described, when a total of 96 photodiodes 132 are used, each of the four output signals has 24 photodiodes associated with it. Keeping the number of photodiodes per signal constant for any resolution improves post-processing of the signal.

Further, in the optical encoder 100 described above, the switching of the resolution is performed during the operation of the optical encoder 100 by using the control mechanism. It is also possible to switch resolutions as a single decision at any time during manufacturing. Regardless of the switching mode, in this example of the invention,
The signal passing through the switch operates quickly and the switch operates slowly.

The form of the invention described is a preferred embodiment, and various changes in the shape, size and arrangement of parts are permitted without departing from the concept of the invention or the scope of the claims. For example, the invention is not limited to rotary encoders. It is also possible to apply to a linear encoder having data tracks arranged in a straight line. The invention is applicable to other resolutions by grouping adjacent photodiodes in various groups, such as groups larger than four. Furthermore, the sensor array may be realized in the form of a semiconductor chip separated from the opto-ASIC chip. Moreover, various optical principles can be implemented according to the present invention, such as the emitted light arrangement shown in FIG. 1 and the reflected light arrangement shown in FIG.

In another example, shown schematically in FIGS. 14 and 15, a porcelain encoder 300 having the same principle as the encoder 100 already described is provided in FIGS.
The optical encoder of has been changed. 14-17, like numbers are used for elements similar to those shown in FIGS. 1-13. In the porcelain encoder 300,
No light source is needed. Furthermore, the data tracks 304 of the rotatable code gear 302 mounted on the shaft have alternating regions with different porcelain properties. Detector array 318, incremental detector array 326 and index and detector arrays 328, 330 are similar to detector arrays 132, 134, 136, respectively. In this case, the photodiodes 132, 134, 136 are the magnetic field detector 3
It has been replaced with 32,334,336. Detector array 3
The signal generated by 26 is processed and the resolution of the porcelain encoder 300 is processed and controlled by the semiconductor chip 338. The circuit is then similar to the circuit shown in FIGS. 13A-B.

In the arrangement of reflected light described above, the optical encoder of FIGS. 1-13 is modified so that the optical encoder 400 having the same principle as the encoder 100 described above is provided. In FIG. 18, similar numbers are used for elements similar to those shown in FIGS. 1-13. In the optical encoder 400, the scanning unit 10
Light source 100 such that 6'has a detector array 118.
Are installed with respect to the semiconductor chip 138. Further, the code gear 102 includes a light source 110 and a reflection lens 402.
The reflective lens 402 is installed so as to be positioned between and. Therefore, the light is transmitted to the detector array 118,
Light from the light source 110 passing through the rotatable code gear 102 is reflected by the reflective lens 402 back to the code gear 102 to reach the incremental detector array 126 and the index and detector arrays 128, 130. The signals produced by the detector array 126 are processed and the resolution of the optical encoder 400 is processed and controlled by the semiconductor chip 138. The circuit is then similar to the circuit shown in FIGS. 13A-B.

[Brief description of drawings]

FIG. 1 is a schematic side view of an embodiment of an encoder having a photodiode array of the present invention.

FIG. 2 is an enlarged view of an encoder having the photodiode array of FIG.

3 schematically illustrates the encoder and photodiode array of FIG. 1 when configured to provide 1012 resolution and 1012 resolution disk patterns.

FIG. 4 is a schematic enlarged view of a transmission gate of the encoder and the photodiode array of FIG.

5 is a schematic enlarged view of index photodiodes and incremental photodiodes of the encoder and photodiode array of FIG. 3. FIG.

6 schematically illustrates the encoder and photodiode array of FIG. 1 when configured to provide a 506 resolution and a 506 resolution disk pattern.

7 is a schematic enlarged view of a transmission gate of the encoder and the photodiode array of FIG.

FIG. 8 is a schematic enlarged view of an index photodiode and an incremental photodiode of the encoder and photodiode array of FIG.

9 schematically illustrates the encoder and photodiode array of FIG. 1 when configured to provide a 253 resolution and a 253 resolution disk pattern.

10 is a schematic enlarged view of a transmission gate of the encoder and the photodiode array of FIG.

11 is a schematic enlarged view of an index photodiode of the encoder and the photodiode of FIG.

FIG. 12 (A) is a schematic top view of the index array of FIGS. 1-11. FIG. 12B is a schematic top view of actuated photodiodes of the index array of FIGS. 1-11 when configured to provide index signals for the respective resolution disc patterns of 1012, 506 and 253. FIG. 12C is a schematic top view of actuated photodiodes of the index array of FIGS. 1-11 when configured to provide an index signal for the 1012, 506 and 253 respective resolution disc patterns. FIG. 12D is a schematic top view of actuated photodiodes of the index array of FIGS. 1-11 when configured to provide index signals for the respective resolution disc patterns of 1012, 506 and 253.

FIG. 13 (A) schematically illustrates an embodiment of the processing electronics used in the encoder of FIGS. 1-12, 14-17. (B) schematically illustrates an embodiment of the processing electronics used in the encoder of FIGS. 1-12, 14-17.

FIG. 14 is a schematic side view of an embodiment of the magnetic encoder and detector array of the present invention.

15 schematically illustrates the magnetic encoder and detector array of FIG. 14 when configured to provide 1012 resolution and 1012 resolution disc patterns.

16 schematically illustrates the magnetic encoder and detector array of FIG. 14 when configured to provide a 506 resolution and a 506 resolution disk pattern.

17 schematically illustrates the magnetic encoder and detector array of FIG. 14 when configured to provide a 253 resolution and a 253 resolution disk pattern.

FIG. 18 is a schematic side view of a second embodiment of the optical encoder and detection array of the present invention.

[Explanation of symbols]

100 optical encoder 102 code gear 104 data tracks 106 scanning unit 110 light source 112 lens 114 light 116 modulated light 118 Photodetector array 120 detection system 122 transparent bar 124 Opaque bar 126 Incremental Photodiode Array 128 index photodiode array 130 index photodiode array 132 photodiode 134 Photodiode 136 photodiode 138 Opt-ASIC semiconductor chip 139 PC board 140 conductor 142 conductor 144 Incremental data resolution selection unit 146 Incremental data resolution selection unit 148 Incremental data resolution selection unit 152 Output signal line 153 Index resolution selection unit 154 Switching signal line 156 switching signal line 158 switching signal line 160 semiconductor switch 200 Impedance conversion amplifier 201 comparator 202 Impedance conversion amplifier 203 comparator 204 data processing element 206 output signal 212 interface 214 Digital Logic 216 Interpolator 218 data pulses 220 data pulses 222 index pulse 224 Communication unit 230 output terminals 232 output terminal 234 output terminal 300 magnetic encoder 302 code gear 304 data track 318 detector array 326 Incremental Detector Array 328 Index / Detector Array 330 Index / Detector Array 332 Magnetic field detector 334 Magnetic field detector 336 Magnetic field detector 400 optical encoder 402 reflective lens

   ─────────────────────────────────────────────────── ─── Continued front page    (71) Applicant 390014281             DR. JOHANES HEIDEN             HAIN GESELLSCHAFT M             IT BESCRANKTER HAF             TUNG (72) Inventor Ruth E. Franklin             California, United States             93108, Santa Barbara, Coyote Ro             744 (72) Inventor Richard M. Forsuit             Austria, Graz, Styra             -Gasse, 39 F term (reference) 2F103 BA38 BA43 CA02 DA01 DA11                       EB12 EB16 EB33

Claims (47)

[Claims] 01. An optical encoder for providing position information of an object moving along a particular measuring direction, the optical encoder comprising: a light source emitting light; data mounted on the object moving relative to the light source. Track; comprising a detection system for receiving modulated light from this data track and generating a position signal from this received light, the data track for receiving light having alternating optical properties of a particular resolution It consists of multiple areas,
The detection system comprises: a photodiode array which receives the modulated light from the data track; a resolution selection unit connected to the photodiode array, the resolution selection unit controlling the resolution of the photodiode array. And select, in this case,
All photodiodes associated with this photodiode array are activated regardless of the resolution selected by the resolution selection unit. 2. The optical encoder according to claim 1, wherein the plurality of alternating regions having different optical characteristics are composed of alternating transparent regions and opaque regions having a specific resolution. 03. The optical encoder of claim 1, wherein the resolution selection unit controls the resolution by controlling the effective size of the detection area corresponding to the photodiodes of the photodiode array that produces the output signal. 04. The optical encoder of claim 1, wherein the resolution selection unit defines a plurality of groups of photodiodes in a photodiode array. 05. The optical encoder of claim 4, wherein the group of photodiodes comprises a single photodiode. 06. The resolution of the photodiode array is
The optical encoder according to claim 5, which is 1012. 07. The optical encoder of claim 4, wherein the group of photodiodes comprises at least two adjacent photodiodes. 08. The resolution of the photodiode array is
The optical encoder according to claim 7, which is 506. 9. The optical encoder of claim 4, wherein the group of photodiodes is composed of at least four adjacent photodiodes. 10. The resolution of the photodiode array is
The optical encoder according to claim 9, which is 253. 11. One of the groups of photodiodes corresponds to a first phase of a first output signal,
The optical encoder according to claim 4, wherein a second group of these groups corresponds to the second phase of the second output signal. 12. One of the groups of photodiodes corresponds to a first phase of a first output signal,
The second group of these groups corresponds to the second phase of the second output signal, and the third group of these groups is
An optical encoder according to claim 4, corresponding to a third phase of the third output signal, the fourth group of these groups corresponding to the fourth phase of the fourth output signal. 13. The method of claim 12, wherein the first phase is 0 °, the second phase is 90 °, the third phase is 180 °, and the fourth phase is 270 °. Optical encoder. 14. One of the groups of photodiodes corresponds to a first phase of a first output signal,
The second group of these groups corresponds to the second phase of the second output signal, and the third group of these groups is
An optical encoder according to claim 5, corresponding to a third phase of the third output signal, the fourth group of these groups corresponding to the fourth phase of the fourth output signal. 15. The method according to claim 14, wherein the first phase is 0 °, the second phase is 90 °, the third phase is 180 °, and the fourth phase is 270 °. Optical encoder. 16. One of the groups of photodiodes corresponds to a first phase of a first output signal,
The second group of these groups corresponds to the second phase of the second output signal, and the third group of these groups is
Optical encoder according to claim 7, corresponding to a third phase of the third output signal, the fourth group of these groups corresponding to the fourth phase of the fourth output signal. 17. The method of claim 16, wherein the first phase is 0 °, the second phase is 90 °, the third phase is 180 °, and the fourth phase is 270 °. Optical encoder. 18. One of the groups of photodiodes corresponds to a first phase of a first output signal,
The second group of these groups corresponds to the second phase of the second output signal, and the third group of these groups is
Optical encoder according to claim 9, corresponding to a third phase of the third output signal, the fourth group of these groups corresponding to the fourth phase of the fourth output signal. 19. The method of claim 18, wherein the first phase is 0 °, the second phase is 90 °, the third phase is 180 °, and the fourth phase is 270 °. Optical encoder. 20. The detection system further comprises a switching signal line, the switching signal line being connected to the resolution selection unit via a plurality of switches, which switches output from the photodiode array. The optical encoder of claim 1, connected to a plurality of output lines, each output line having a particular phase delay associated with it. 21. The optical encoder according to claim 1, wherein the resolution of the photodiode controlled by the resolution selection unit corresponds to a specific resolution of the data track. 22. The optical encoder of claim 1, wherein the data track rotates with respect to the light source. 23. The optical encoder according to claim 1, wherein the data track is mounted on a code gear mounted on a rotary shaft. 24. The photodiode array is an optical
The optical encoder according to claim 1, which is arranged on an ASIC semiconductor chip. 25. A method of controlling the resolution of an optical encoder that provides position information of an object moving along a particular measurement direction, the optical encoder comprising a light source emitting light, and data moving relative to the light source. The method comprises: directing modulated light from a data track to a plurality of photodiodes of a detection system having a resolution of a first value; from this first value to a second value. Changing the resolution of the detection system to a second value without changing the placement of the photodiodes of the detection system during the change. 26. The method of claim 25, wherein altering the resolution comprises altering the effective size of the detection area corresponding to the number of photodiodes producing the output signal. 27. The method of claim 25, wherein the modification defines a group of photodiodes. 28. The method of claim 27, wherein the group of photodiodes comprises at least two adjacent photodiodes. 29. The method of claim 27, wherein the group of photodiodes comprises at least four adjacent photodiodes. 30. A first from signals generated from one of the defined groups of photodiodes
Generating a first output signal in phase; generating a second output signal in second phase from signals generated from a second one of the defined groups of photodiodes. 28. The method according to 28. 31. A first from signals generated from one of the defined groups of photodiodes
Producing a first output signal in phase; Producing a second output signal in second phase from a signal produced from a second one of the defined groups of photodiodes; Defining a photodiode Generating a third output signal of a third phase from a signal generated from a third one of the defined groups; generated from a fourth one of the defined groups of photodiodes 29. The method of claim 28, comprising: producing a fourth output signal of a fourth phase from the received signal. 32. The first phase is 0 °, the second phase is 90 °, the third phase is 180 °, and the fourth phase is 270 °. Method. 33. An optical encoder providing position information of an object moving along a particular measuring direction, the optical encoder comprising: a light source emitting light; data mounted on the object moving relative to the light source. Track; comprising a detection system for receiving modulated light from this data track and generating an index signal from this received light, the data track for receiving light having alternating optical properties of a particular resolution This detection system consists of multiple regions: an index photodiode array that receives this light from this data track and produces an index signal; it consists of a resolution selection unit connected to this photodiode array, The selection unit controls the contrast of this index signal, In this case, all photodiodes associated with this photodiode array are activated regardless of the resolution selected by this resolution selection unit. 34. The optical encoder of claim 33, wherein the alternating regions of different optical properties are comprised of alternating transparent and opaque regions of a particular resolution. 35. The optical encoder of claim 33, further comprising a second photodiode array that receives light from the data track and generates a second index signal. 36. The optical encoder of claim 33, wherein the resolution selection unit selectively activates a plurality of photodiodes in the index photodiode array to optimize the index signal. 37. The specific resolution of the code track is 10
The optical encoder according to claim 36, wherein the optical encoder is 12. 38. The specific resolution of the code track is 50
The optical encoder according to claim 36, wherein the optical encoder is 6. 39. The specific resolution of a code track is 25
The optical encoder according to claim 36, wherein the optical encoder is 3. 40. The optical encoder of claim 33, wherein the data track rotates with respect to the light source. 41. The optical encoder of claim 33, wherein the data track is mounted on a code gear mounted on the rotary shaft. 42. The optical encoder according to claim 33, wherein the index photodiode array is arranged on an opto-ASIC semiconductor chip. 43. A method of controlling an index signal of an optical encoder that provides position information of an object moving along a particular measurement direction, the optical encoder being a light source emitting light, and moving relative to the light source. Composed of data tracks and having a given resolution, the method is: directing light from the data tracks to a plurality of photodiodes of the index photodiode array; The index signal is formed by changing the activation state of one or more of the photodiodes in the index photodiode array without changing the arrangement of the diodes. 44. The method of claim 43, wherein the modifying optimizes the index signal based on the resolution of the data tracks. 45. An optical encoder for providing position information of an object moving along a particular measuring direction, the optical encoder comprising: a light source emitting light; data mounted on the object moving relative to the light source. Track; comprising a detection system for receiving modulated light from this data track and generating an index signal from this received light, the data track for receiving light having alternating optical properties of a particular resolution The detection system consists of multiple regions: a photodiode array that receives the modulated light from the data track; an index photodiode array that receives light from the data track and generates an index signal; It consists of a resolution selection unit connected to a photodiode array, The resolution selection unit controls the resolution of the photodiode array to control the contrast of the index signal. 46. A method of controlling the resolution of an optical encoder that provides position information of an object moving along a particular measurement direction, the optical encoder comprising a light source emitting light, and data moving relative to the light source. The method comprises: directing modulated light from a data track to a plurality of photodiodes of a detection system having a first value of resolution; Aiming at multiple photodiodes in a diode array; this first
Changing the resolution of the detection system to a second value without changing the placement of the plurality of photodiodes of the detection system during the change from the value of to the second value of the index photodiode array. Changing the start-up state of one or more of the photodiodes of the index photodiode array to form the index signal without changing the arrangement of the photodiodes of the. 47. In a porcelain encoder providing position information of an object moving along a particular measuring direction, the porcelain encoder comprising: a data track mounted on the object moving relative to the detector system; It consists of a detection system that receives porcelain energy from a truck and produces a position signal from the received porcelain energy, the data track consisting of alternating regions of different porcelain characteristics with a specific resolution. The system consists of: a detector array that receives this porcelain energy from this data track; a resolution selection unit connected to this photodiode array, which resolution selection unit controls and selects the resolution of this photodiode array. , In this case all the detectors associated with this detector array. The dispenser fires regardless of the resolution selected by this resolution selection unit.